In logging operations, processors are typically used to delimb, measure and cut logs. In contrast, loaders are used to move, sort and load logs onto a logging trailer. Some loaders include a log grapple with hydraulically powered hinged jaws. The log grapple is generally mounted to a boom, which is mounted in turn on a base such as an excavator. The loader is used to move logs toward a desired position, such as the logging trailer or toward the loader itself. The logs are moved by extending the boom, closing the hinged jaws around the log, and moving the boom inward to slide the log toward the desired position. The log is then released and the boom is re-extended to position the grapple closer to the center of gravity of the log. This allows the log to be grasped near its center of gravity to be moved closer to the desired position.
Skidders and yarders are frequently used to drag or haul individual logs to a landing for loading. Alternatively, in shovel logging, an excavator with a boom-mounted logging grapple is used to move fallen trees or logs toward the landing. As the excavator reaches an area with fallen trees or logs, the boom is extended and the grapple is used to grasp one end of a log. The excavator raises the boom to lift the log, turns 180 degrees, and then releases the log to move the log nearer to the landing. The remaining trees or logs within reach are moved in the same manner. If the distance to the landing exceeds the reach of the boom and grapple, the excavator is then repositioned and the process is repeated as needed in order to move the trees or logs the remaining distance to the landing.